The Allen Bradley 1769-SM2 is a Compact I/O communication module designed to provide serial communication capabilities for CompactLogix and MicroLogix 1500 controllers. It is primarily used to connect PLC systems with external devices through Modbus RTU or DSI (Drive Serial Interface) protocols.
This module is commonly applied in industrial systems that integrate legacy drives, energy meters, or serial field devices into a CompactLogix architecture.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Allen Bradley (Rockwell Automation) |
| Catalog Number | 1769-SM2 |
| Module Type | Serial Communication Module |
| Protocols Supported | Modbus RTU, DSI |
| Supported Modes | Master / Slave (Modbus RTU) |
| Drive Compatibility | PowerFlex 4 / 7 Series |
| Communication Channels | Up to 3 channels |
| Baud Rate Range | 9600 – 38,400 bps |
| Backplane Current Draw | ~350 mA at 5V DC |
| Power Supply Requirement | From Compact I/O backplane |
| Mounting Type | DIN rail / Panel mount |
| Operating Temperature | 0°C to 60°C |
| Storage Temperature | -40°C to 85°C |
| Module Width | 1 slot (Compact I/O) |
| Dimensions | Approx. 118 × 35 × 87 mm |
| Weight | Approx. 0.36 – 0.52 kg |
System Role in Automation Architecture
The 1769-SM2 acts as a serial communication bridge inside CompactLogix systems. It enables PLCs to communicate with non-Ethernet industrial devices using standard serial protocols.
Typical roles include:
- Modbus RTU master/slave communication
- Drive integration via DSI protocol
- Data exchange with energy meters and sensors
- Legacy serial device connectivity in modern PLC systems
It is often used in hybrid automation systems combining Ethernet and serial field networks.
Recommended Related Modules
| Model | Function |
|---|---|
| 1769-L33ER | CompactLogix Controller |
| 1769-PA2 | AC Power Supply Module |
| 1769-PB4 | DC Power Supply Module |
| 1769-IF8 | Analog Input Module |
| 1769-OB16 | Digital Output Module |
| 1769-ECR | End Cap Module |
Common Allen Bradley System Modules
| Model | Function |
|---|---|
| 1756-EN2T | EtherNet/IP Communication Module |
| 1756-L81E | ControlLogix Processor |
| 1734-AENTR | POINT I/O Ethernet Adapter |
| 5069-IB16 | Compact 5000 Input Module |
| 2711P-T10C4D8 | PanelView HMI Terminal |
| 2080-LC50-48QWB | Micro850 Controller |
